The decline bench press may function as an adjunct to the flat bench press but not as a replacement for the flat bench press. The decline bench press allows you to use a little more weight but at the expense of range of motion. Depending on your structure, the decline bench press may place more strain on your shoulder joints. Consult a health care professional before beginning any exercise.
The pectoralis major are the two large muscles that cover your chest. The primary function of the pair is to adduct your humerus, or pull your arm into the center of your body. This is why your chest is active on the bench press. As you push the bar to lockout, your upper arm moves from a position as far as possible from the mid-line of your body to as close as possible to the mid-line of your body.
Decline Bench Press
The decline bench press is performed in a manner similar to the flat bench press. Unlike the flat bench, a decline bench often has a leg attachment that you wrap your knees around to hold yourself in position. When using the decline bench press, you must bring the bar slightly lower on your chest. Attempting to bring the bar higher on your chest may place an uncomfortable strain on your shoulders. You will need to experiment to determine the best position for you to use.
Pros of Bench
An immediate advantage of the decline bench press is that you can, with proficiency, use more weight. The larger fibers of your muscles will be stimulated by the increase in weight lifted, which may have a small positive effect on your ability to build size and strength. Another advantage is the greater activation of the lower portion of your chest. In a 1997 study published in the "Journal of Strength and Conditioning Research," the decline bench press was shown to significantly increase the activation of the lower pectoralis major.
Cons of Bench
The decline bench press gives you have a limited range of motion. You can use more weight because of both mechanical advantage and less total work being performed. By only bringing the bar down to your lower chest, you severely limit the distance you move the bar. In a 1995 study published in the "Journal of Strength and Conditioning Research," the limited range of motion of the decline bench press was shown to limit the activation of the triceps and the anterior deltoids. So while there may be a slight increase in activation of the lower portion of the pectoralis major, there is significantly less activation of other muscles.